Metering apparatus for mixing machines



Dec. 11, 1935. v s A E EAL 2,025,003

METERING APPARATUS FOR MIXING MACHINES Filed Au 18, 1931 2 Sheets-Sheet 1 Dec. 17, 1935. s SHAFER, JR" AL 2,025,003

METERING APPARATUS FOR MIXING MACHINES Filed Aug. 18, 1931 2 Sheets-Sheet 2 (Gil D 3 4 l 5 l F1 5. a. 3

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Patented Dec. 17, 1935 UNITED STATES Search mom PATENT OFFICE METERING APPARATUS FOR llflXING MACHINES Samuel Shafer, Jr., and Charles F. Ball, Milwaukee, Wis., assignors to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application August 18, 1931, Serial No. 557,904

1 Claim. (01. 8373) The present invention relates to mechanism for metering industrial operations. We have illustrated in this case, which is a continuation in part of our application filed August 2, 1927, Serial No. 210,203, which has since matured into Patent No. 1,827,879 dated October 20, 1931 the invention as used in connection with mechanism for mixing concrete. In one illustrated embodiment of the invention it is shown adapted for use in connection with a batch concrete mixer; and in another embodiment as especially adapted for use with a transit or delivery truck concrete mixer.

In the accompanying drawings:

Figure l is a front view of a batchmeter embodying the invention, the front plate of the casing in which the mechanism is supported being omitted;

Figure 2 is a top plan view of the mechanism shown in Figure 1, the casing being shown in section;

Figure 3 is a diagrammatic view illustrating the invention and representing the batchmeter as one element of means for the automatic control of a machine whose operations are being metered, the specific mechanism shown being especially designed for use with a batch concrete mixer; and

Figure 4 is a diagrammatic view illustrating the batchmeter or timing device as an element in means for the automatic metering of a transit or truck concrete mixer.

In this specification the term batchmeter is employed to designate a mechanism, constituting one feature of the present invention, that is adapted to meter or time the operations of a machine to which such batchmeter is applied, and to automatically give a signal when such machine has operated a sufficient length of time, or for a suqflcient number of operations, to produce the desired results, or to meet working requirements.

Referring particularly to Figures 1 and 2 of the drawings, 2 designates the casing in which the mechanism of the batchmeter is supported. In this casing a main power shaft 3, serving as a driving element is supported. This shaft is preferably provided with a wheel 4 located upon the outside of the casing and connected by chain 5 with a source of power, not represented in the drawings, but which may be any available shaft of the apparatus to which the batchmeter or counting device is applied, it being understood that such shaft is preferably one that is in constant revolution whenever the apparatus or machine whose movements are being metered is in operation.

The shaft 3 carries on the inside of the casing a pinion 6 which gears with a wheel 1, loosely supported upon a shaft 8. 9 designates a disk, against one face of which rests the wheel 1, the disk being preferably integral with the shaft 8. In the periphery of the disk is formed a recess I in which lies the outer end of a pawl II carried by the wheel 1. This arrangement insures that the disk 9 shall be turned whenever the wheel 1 is rotated in the direction of the arrow a, Figure l, but will not be turned if the direction of the wheel be reversed, since the pawl is spring-held, and will hence ride over the disk without imparting motion thereto on a reverse movement of the wheel. An eccentrically disposed pin 12 is carried by the disk 9.

The mechanism thus far described constitutes a gear train through which the meter is driven from a shaft or other source of power forming part of, or closely associated with, the apparatus whose operations are being timed or measured.

l3 indicates a metering wheel within the casing and loosely mounted upon a shaft or other support, this wheel being incorporated into the gear train just referred to. It is formed with a series of peripheral teeth I 4, the uniform succession of which is broken at a point in the circumference of the wheel to form a dwell or open space l between teeth, in which moves the pin l2 projecting from the disk 9 whenever the meter is inactive, the length of the dwell being sufficient to permit the pin I! to revolve therein without engaging either tooth l4 bounding such space.

It will be understood that the pin l2, which in effect is a one tooth driving wheel, engages successively with the teeth H of the metering device and so moves it, as will be presently herein more fully described, whenever the meter is brought into operation. When the meter is to be started from a condition of rest or inaction, the wheel I3 is advanced in the direction of the arrow 0, Figure 1, sufiiciently far to cause the pin I2 to engage with the tooth next adjacent to the space l5, after which the wheel will be slowly turned by the successive revolutions of the pin l2, until practically a complete revolution of the wheel has been effected, and the driving pin or tooth l2 again comes into the space 15, whereupon rotation of the timing or metering wheel ceases, although the disk and the pin which it carries, continue to revolve. To indicate a complete rotat on of the metering wheel iii the meter is preferably provided with a bell l8 formed with a spring-operated plunger I! that is engaged by lever l8 carrying a contact roller l9. Secured to the wheel I3 is a block or projection 20, the position of which is such that at every rotation of the wheel the block engages with the contact roller l9, moving the lever l8 and causing a signal to be sounded by the bell IS. The block 20 is adjustable being secured to the wheel by a pin or screw 2! adapted to engage with any one of a series of openings formed therefor in the wheel, as represented in Figure 1.

In order to advance the metering wheel l3 sumciently to have its teeth engaged by the tooth l2 of the driving wheel 9, there is provided an arm 22 mounted upon a shaft or other support 50, concentric with the wheel l3. The arm 22 carries a pawl 23 at its outer end adapted to engage with a pin or projection 24 on the wheel [3. The shaft 50 is arranged to be rocked from the outside of the casing through the agency of an arm 25 secured fast to the shaft. The arm may be manually operated or connected with some part of the apparatus whose movements are being timed, so as to give motion to the arm 22 to advance the wheel l3 at the time the meter is to be set into operation.

The mechanism thus far described has been presented and claimed in the aforesaid application Serial No. 210,203 and need not be further here described.

In U. S. Patent No. 1,608,831 to Charles F. Ball, assignor to Chain Belt Company, there is described and claimed a method of controlling the power employed to drive an apparatus such as a concrete mixer from or through a batchmeter, the principle of operation therein described being to control an electric circuit so as to cut ofl the source of power operating the mixing apparatus should attempt be made to discharge a batch of concrete being mixed from the drum during the timing or metering period, that is, before it is properly mixed and in condition to be discharged for use. The meter herein described and illustrated is adapted to operate according to the principle or method of operation described in the said Ball patent, it being incorporated as an element of electric apparatus and improved and devised with special reference to being employed in connection with mixing apparatus, especially concrete mixing apparatus, as will be now pointed out.

Still referring to Figures 1 and 2, 28 indicates a stationary conducting part in the form of a disk which is electrically insulated as indicated at 29. It has connection, through a conductor 32, with one side of an electric circuit 39 leading out from the casing 2. This disk is concentric with the metering wheel l3, being preferably located close to the,face of the latter, as represented in Figure 2. A segment of the disk is cut away as indicated at 33.

30 indicates a contact roller supported at the end of a rather stifl' spring 3| carried by the block 20. It is so positioned that if the wheel rotates relative to the disk 28 the roller 30 engages with the peripheral edge of the disk and therefore makes electrical contact therewith. When, however, it comes opposite to the cut away part 33 this contact is broken and the electric circuit is open at this point. It will be understood that the contact roller 30 is in constant electric connection with a terminal of the circuit 39 leading to the casing 2, through metallic parts such as the spring 3!, block 20, wheel l3 and its supporting shaft. The circuit 39 which has been referred to includes the parts of the meter that have been described, also an electric apparatus whose functioning is vital to the continued operating of the machine being timed or metered, and a circuit opening and closing switch or mechanism connected with and arranged to be directly operated by mechanism that controls the discharge of a mixing machine. In Figures 3 and 4 of the drawings the electric circuit referred to is diagrammatically illustrated. Referring to these views, 38 indicates the piece of electric apparatus whose functioning is essential to the operation of the apparatus being metered and which may be an electric magneto machine. In these views, 4| and 4| indicate the ground connections through which the circuit is completed. As will be seen there are two breaks in the circuit, each controlled by a mechanically operated switch. The switch or circuit making and breaking element of the meter has already been described.

In Figure 3 the invention is illustrated as applied directly to the discharge mechanism of a batch concrete mixer, the delivery from which is controlled by a discharge chute 36. It is well understood that when the chute is in one position such as that indicated in Figure 3, the material in the rotating drum of the concrete mixer should be confined therein, the discharge chute serving as a sort of closure for the drum, but when turned to another position, thematerial will be delivered. The chute is represented as being supported from a shaft 34, the movements of which are controlled by a lever 31. Such lever may be a hand lever or it may be an element of a power-driven mechanism for effecting the movements of the chute 36. The switch or circuit control mechanism that is connected with and directly operated by the discharge chute 36 is preferably located within a casing 33, and consists of a movable circuit closing contact 35, carried by the shaft 34 that supports the discharge chute, with which one side of the circuit 39 connects, and a brush or stationary contact 40 adapted to have engagement with the said movable contact 35. The contact piece 35 is so shaped that when the chute 38 is in non-discharging position the circuit is open, the piece 35 being separated from the brush 40, whereas when the chute is moved to its other position, that is, to deliver the mixed material, the movable contact piece 35 comes into engagement with the brush 40, whereupon the circuit is closed at this point.

It will be seen that the electric apparatus indicated in Figure 3 includes a circuit in which are two breaks controlled by independent mechanisms,one by the meter, and the other directly by the discharge mechanism for the mixing machine. These parts are so related that when the apparatus is properly functioning the circuit is never closed, it being open at one, or the other, or both, breaks. If the parts be so manipulated that both breaks are closed at the same time, the normal functioning of the electric apparatus 38 will be so interfered with as to cause to stoppage of the apparatus being metered, and thus give conclusive proof that something is going wrong.

Proper operation of the apparatus illustrated in Figure 3 requires that the discharge chute 36 should be in the position indicated, that is, in non-discharging position whenever the meter is in operation. Should, however, through accident or fraudulent intent to discharge a batch of con- 75 crete before it is mixed the full time, an operator shift the handle 31 and move the discharge chute to delivery position, the circuit will be instantly closed at this break, by the engagement of the parts 35 and 40, and since the circuit is now closed at the meter, by the engagement of the contact roller 30, with the edge of the disk 28-the meter not having completed its metering operation-the circuit will be completed, grounding the magneto, whereupon the operation of the motor driving the apparatus will be at once arrested. Thus, while there is no mechanical device for positively preventing the operation of the discharge chute at any time, the penalty, which will be automatically and instantly inflicted, by the stopping of the entire apparatus, will make it the part of wisdom for an operator to wait until the meter completes its cycle of movement and gives the signal before attempting delivery of the charge of the mixing machine.

In Figure 4 there is illustrated a different embodiment of the invention wherein the electric apparatus is directly connected for use with the discharge control of a truck or transit concrete mixer. Referring to this view 42 indicates the end of the mixing drum of a truck mixer, supported in stationary frame-work 43. It is formed with a discharge opening through its end adapted to be closed by a plate or cover 44. This closure is supported and controlled in its movements by a series of arms or links 45, which need not be herein described as they constitute the subject matter of another invention. Suffice it to say that they include an arm 46 projecting from a shaft 41 adapted to be controlled by a hand wheel 48. When the hand wheel is turned in the proper direction the shaft 41 is oscillated, the arm 46 is elevated, and the closure 44 is moved away from the opening, permitting the discharge of the material within the drum 42. 49 indicates a link connecting the arm 46 with a movable circuit closing part 35 which is adapted to make engagement with stationary contacts 40" and 40'. As will be seen the contacts 40" and 40' are connected respectively to the opposite ends of the circuit 39 at the break therein which is controlled by the mechanically operated device that controls the discharge from the mixing machine. In the operation of truck mixers it is often required that the material after being charged into the drum 42 shall receive a certain amount of mixing a before it shall be delivered-either in transit or after the truck reaches the place where the con- 5 crete is to be used. To insure that the full amount of mixing shall be had, a meter, like that which has been described and arranged in a casing 2 is supported at a suitable point on the frame of the truck, and the circuit is continued therefrom as diagrammatically illustrated in Figure 4. The contacts that are controlled directly by the movements of the parts which govern the discharge from the drum are mounted within a protecting casing 33' indicated by dotted lines. The operation of the parts represented in Figure 4 it is thought will be understood without further description, being similar to the operation of the mechanism represented in Figure 3, the two mechanisms differing from each other only in details of construction which adapt them to their respective uses.

What is claimed is:

The combination, with the agitating means of a truck mixer, including a receptacle in which the agitation takes place; a motor for operating such agitating means, and a closure for preventing the escape of the material from the receptacle; of a meter device for determining the minimum period for each agitation; an electric circuit, including means whereby the motor may be stopped, a switch in the circuit operated by the metering device and a second switch; and manually operated means arranged to directly and at all times control the movements of the closure, irrespective of the motor-operated means, and also to control the aforesaid second switch in the electric circuit, the parts being constructed and arranged to set the second switch in the circuit in one position when the closure is closed and to another position when the closure is open, whereby should attempt be made to open the receptacle, after the metering device starts to operate and before it completes its cycle of movement, the agitating means will be brought to rest.

SAMUEL SHAFER, JR. CHARLES F. BALL. 

